Radiator efficiency, is measured in British Thermal Units (BTU). The dimensions of a room are used to calculate the BTU output required to heat that room. Radiators all have a known and calculated BTU output. Using the BTU outputs in the Product Specification or description above, it is easy to calculate the size of radiator you need to help provide the total heat output necessary for your room.

How to calculate BTU requirement

The best way is to ask your plumber to perform the calculation for you. If you don't have access to a plumber, you can use the BTU Calculator below as a guide. Please note that the calculated figure relates to the combined heat output of all radiators in the room, therefore the towel rail or radiator that you purchase need not satisfy the entire BTU output if it is used to complement existing radiators.

This calculator is for guidance use only.

1. Please select your required units

Metric (metres)

Imperial (feet)

2. Please enter room measurements

Height of room:

Width of room:

Length of room:

Window Area x²:

3. Please select type of room:

4. What is below the room?

5. What is above the room?

6. Please select type of outside walls:

7. Please select type of windows:

8. Please select number of outside walls:

Watt/BTU requirements:

Watts Required:

BTU's Required:

Essential Extras Available (will be displayed when product added to basket)